1. Field of the Invention
The present invention relates to endotracheal tubes of the type used in the oral intubation of small children, neonate and premature neonate patients, and more particularly to such endotracheal tubes that include a radially extending flange that rests upon the arytenoid cartilages within the larynx of the intubated patient, thereby limiting the depth for which the endotracheal tube can be advanced into the trachea and providing a base point from which the depth of the endotracheal tube below the vocal cords can be measured.
2. Prior Art Description
Accidental right mainstream endotracheal intubation is a common cause of pulmonary morbidity (i.e. lung collapse, hypoxemia, cardiac arrest, etc.) in all patients undergoing an endotracheal intubation procedure. Accidental right mainstream endotracheal intubation occurs when an endotracheal tube is advanced too far within a patient's trachea. In such a situation, the endotracheal tube enters the right bronchi of the lung causing the left lung to collapse. Such accidental right mainstream endotracheal intubation results in many deaths each year and causes surviving patients to incur extensive pulmonary care. The dangers of accidental right mainstream endotracheal intubation is of particular concern during the intubation of small children, neonate and premature neonate patients. With such patients, the physical length of the patient's trachea is very short. Additionally, the lungs of such patients are often weak, leaving the patient particularly susceptible to the disastrous consequences of accidentally advancing an endotracheal tube beyond the trachea and into the bronchi of a lung.
As will be recognized by a person skilled in the art, the trachea lays between the larynx of a patient and the left and right bronchi of a patient's lungs. To properly perform an endotracheal intubation procedure, the distal end of an endotracheal tube must be positioned within the patient's trachea. If the distal end of an endotracheal tube were to move out of the trachea, above the larynx, the vocal cords may close, preventing the intubation of the lungs and possibly causing such consequences as suffocation or should the vocal cords not close, gastric content aspiration could occur. If the distal end of the endotracheal tube descends below the trachea, the endotracheal tube typically enters the right mainstream bronchus of the lung causing the pulmonary morbidity effects previously described.
In the prior art there exist many features designed into endotracheal tubes to assist in positioning the distal end of the endotracheal tube within a patient. One of the most common features designed into prior art endotracheal tubes is the use of distance indicators printed onto the exterior surface of the endotracheal tube. The distance indicators are indicative of the distance between the distal end of the endotracheal tube and the marking itself. For example, if an orally applied endotracheal tube is advanced down a patient's throat until an indication of fifteen centimeters is seen at the patient's mouth, the person administering the endotracheal tube can see that the endotracheal tube has been advanced fifteen centimeters into the patient's mouth and into the patient's throat. By knowing the size of the patient, the person administering the endotracheal tube can estimate the intubation distance needed to position the distal end of the endotracheal tube properly within the patient's trachea. Such estimated positioning is obviously only as accurate as the skills of the person positioning the endotracheal tube. Additionally, endotracheal tubes that rely solely on distance indicators for placement must be used in conjunction with an external endotracheal tube restraint devices to ensure the distal end of the endotracheal tube does not move after it is placed within a patient's trachea.
In the prior art, the exact placement of the endotracheal tube can only be checked via an X-ray image. Consequently, an X-ray imaging device is often used when intubating a patient with an endotracheal tube. The X-ray imaging device allows the person administering the endotracheal tube to place the distal end of the tube in a patient's trachea with greater accuracy. However, such a procedure exposes both the patient and the attending medical personnel to unnecessary dosages of X-ray radiation. Furthermore, X-ray facilities are seldom available on an emergency basis.
Another prior art device that helps in the placement of the distal end of an endotracheal tube in the trachea of a patient is the use of inflatable bladders positioned near the distal end of the endotracheal tube. With such devices, the endotracheal tube is placed down a patient's throat. When the distal end of the endotracheal tube becomes properly positioned within a patient's trachea, the bladder is inflated. The inflated bladder contacts the interior walls of the trachea, substantially anchoring the endotracheal tube into a set position. In the art of endotracheal intubation, such endotracheal tubes that include such inflatable bladders are said to be "cuffed". Cuffed endotracheal tubes have the disadvantage of being both expensive and difficult to manufacture. Furthermore, the inflatable bladder on cuffed endotracheal tubes increases the overall diameter of the distal end of the endotracheal tube. As a consequence, cuffed endotracheal tubes are not preferred on small children, neonate and premature neonate patients. The extremely narrow larynx and trachea of such patient's makes the use of cuffed endotracheal tubes unpractical. Furthermore, since small children, neonate and premature neonate patients have very sensitive trachea walls, the use of cuffed endotracheal tubes with such patients may inflame the tissue within the trachea as the bladder is inflated, thereby causing the risk of the patient's trachea swelling closed or otherwise severely restricting air flow to the lungs.
Since cuffed endotracheal tubes are not desirable for small children, neonate and premature neonate patients, uncuffed endotracheal tubes are commonly used, leaving the person performing the endotracheal intubation to rely solely upon the radiopaque distance indicator lines to properly position the endotracheal tube. Since the length of the trachea in such patients is extremely short, the proper placement of the endotracheal tubes becomes even more of an exacting procedure. Furthermore, the use of X-ray imaging to help in the placement of uncuffed endotracheal tubes is also undesirable because the X-ray radiation produced by the X-ray imaging is an added danger to small children, neonate and premature neonate patients. As a result, medical personnel who want to limit X-ray radiation exposure to their patients are left with little alternative but to visually rely upon the distance indicators of an endotracheal tube outside the patient's body to estimate proper location of the distal end of the endotracheal tube within the trachea of the patient.
In view of the needs that exist in the prior art, it is a primary objective of the present invention to provide an endotracheal tube that provides medical personnel placing the endotracheal tube within a patient, a positive indication that assures the administering personnel that the distal end of the endotracheal tube is properly positioned within a patient's trachea.
It is a further objective of the present invention to provide such an endotracheal tube that is small in size so as to be readily used on small children, neonate or premature neonate patients.